Methods and system for generating three-dimensional spatial images

ABSTRACT

The disclosure is directed to a 3D imaging system that generates a three-dimensional (3D) spatial image of a source content, e.g., images or videos. The source content is a two-dimensional (2D) color-encoded content in which different portions of the source content are encoded with different colors based on a depth at which the corresponding portion is to be formed relative to the other portions in the 3D spatial image. The 3D imaging system includes an optical component, e.g., a Fresnel lens, to generate the 3D spatial image. In the aerial viewing configuration of the 3D imaging system, the 3D imaging system generates the 3D spatial image in a space between the optical component and a viewer. In the infinity viewing configuration of the 3D imaging system, the 3D imaging system generates the 3D spatial image in a space between the optical component and optical infinity.

BACKGROUND

Spatial displays viewed without user worn apparatus, such asautostereoscopic displays, integral imaging displays, volumetricdisplays, holographic displays, aerial-image displays, and infinitydisplays present images which appear to have various spatial qualities.These and other various spatial display technologies have widely varyingspatial qualities, imaging methods, limitations, physical constructionand spatial image presenting capabilities. Autostereoscopic displays,such as the parallax barrier or lenticular methods, provide a multitudeof viewing zones at different angles with the image in each zoneappropriate to that point of view. Typically, a fine vertical grating orlenticular lens array is placed in front of a two-dimensional (2D)display screen. A stereoscopic image is divided into two alternatingvertical bands, comprising alternating left/right views, and displayedon the 2D display screen. If the observer's eyes remain fixed at aparticular location in space, then one eye can see only the right viewbands through the grating or lens array, and the other eye can see onlythe left view bands. The eyes of the user must be within separate butadjacent viewing zones to see a stereoscopic image, and the viewing zonemust be very narrow to prevent image distortions as the observer movesrelative to the display. These techniques have several drawbacks.

Autostereoscopic displays typically require a large display resolution.Each eye sees only half the horizontal screen resolution, therefore theimage's resolution is significantly reduced. If the displays providemultiple views of a stereoscopic image, each view provided lowers thedisplay's resolution in half. Also, the observer must remain withinviewing zones. Additionally, as the observer focuses on a single plane,conflicts between convergence and accommodation rapidly lead toeyestrain. The observer cannot focus on images of varying depth, as withother three-dimensional spatial displays, such as volumetric orholographic displays.

Projection devices are known in the art that project images so that theyappear to float in the air. Most prior art aerial projection systemstypically use a three-dimensional (3D) physical object as the source ofthe image. However, this cannot produce an arbitrary or moving image.Some methods produce floating images by either reflecting an electronicdisplay from one or more curved mirrors, viewing an electronic displaythrough an optical system comprised of retroreflectors combined withbeam splitters or viewing an electronic display placed behind one ormore lenses. These methodologies are termed reflective real-imagedisplays or transmissive real-image displays, respectively. The imageryproduced by a typical real-image display, is typically planar. Theimagery has some spatial qualities, but the image otherwise has no true3D spatial qualities.

Some methods create transmissive floating planar imagery from anelectronic display placed behind a first Fresnel lens located behind asecond Fresnel lens, which focus the light from the image source infront of the second Fresnel lens. They may also combine two floatingplanar images by aligning two image sources with two pairs of Fresnellens (4 lenses in total), and optically combining them with a singlehalf-silvered mirror (beam splitter). Two planar images are viewed by anobserver, both floating in space, one in front of the other, comprisedof 2D foreground and background imagery. Some of these methods sufferfrom the fact that both floating planar images appears to float withinthe housing, rather than preferably extending beyond the housing forincreased viewability and impression of spaciousness. Additionally, theimagery produced by the two full set of optics and displays, has limitedspatial impression as the imagery is merely comprised of two overlappingplanar images separated by a small amount of space. More specifically,the imagery is lacking true three-dimensionality, as it has no smooth ordeep spatial visual qualities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example illustrating chromaticaberration phenomenon of an optical component, consistent with variousembodiments.

FIG. 2 is a block diagram of an aerial viewing configuration of a 3Dimaging system, consistent with various embodiments.

FIG. 3 is an example 3D spatial image generated by the 3D imaging systemin the aerial viewing configuration of FIG. 2, consistent with variousembodiments.

FIG. 4 is another example 3D spatial image generated by the 3D imagingsystem in the aerial viewing configuration of FIG. 2, consistent withvarious embodiments.

FIG. 5 is a block diagram of a mask system used with the 3D imagingsystem, consistent with various embodiments.

FIG. 6 is a top view of the aerial viewing configuration of the 3Dimaging system, consistent with various embodiments.

FIG. 7 is an example of an artist's rendition of a viewing setting forthe aerial viewing configuration, consistent with various embodiments.

FIG. 8 is another example of a viewing setting for the aerial viewingconfiguration, consistent with various embodiments.

FIG. 9 is an example of a silhouette used in the aerial viewingconfiguration, consistent with various embodiments.

FIG. 10A is a block diagram an infinity viewing configuration of the 3Dimaging system, consistent with various embodiments.

FIG. 10B is a top view of the infinity viewing configuration of the 3Dimaging system, consistent with various embodiments.

FIG. 10C is another top view of the infinity viewing configurationillustrating window parallax phenomenon, consistent with variousembodiments.

FIG. 11A is a picture of an example viewing setting of the infinityviewing configuration of the 3D imaging system, consistent with variousembodiments.

FIG. 11 B is a picture of a 3D spatial image generated by the infinityviewing configuration of the 3D imaging system of FIG. 11A, consistentwith various embodiments.

FIG. 12 is a block diagram of an environment in which the disclosedembodiments can be implemented, consistent with various embodiments.

FIG. 13 is a relationship map that depicts relationships between a zoomparameter and other parameters of an image, consistent with variousembodiments.

FIG. 14 is an example picture of a human subject captured usingtraditional green screen techniques for generating a 2D color-encodedcontent, consistent with various embodiments.

FIG. 15 is an example picture of the color-encoded human subject of FIG.14 displayed as a 3D spatial image in the infinity viewing configurationof the 3D imaging system, consistent with various embodiments.

FIG. 16 is a block diagram illustrating an area of attention in whichfront or foreground objects of a 3D spatial image are to be formed,consistent with various embodiments.

FIG. 17A is an example picture of a color encoded 2D image withcircumferential peripheral background and scene objects centered aroundarea of attention, consistent with various embodiments.

FIG. 17B is an example picture of a 3D spatial image generated from thecolor encoded 2D image of FIG. 17A in the infinity viewingconfiguration, consistent with various embodiments.

FIG. 18 is a flow diagram of a process for generating a 3D spatial imageusing the 3D imaging system, consistent with various embodiments.

FIG. 19 is a block diagram of a processing system that can implementoperations, consistent with various embodiments.

DETAILED DESCRIPTION

Embodiments are directed to generating three-dimensional (3D) spatialimages that can be viewed without any user-worn apparatus. A 3D imagingsystem includes an optical component that receives a two-dimensional(2D) content, e.g., a 2D image, from an image source and generates a 3Drepresentation of the 2D content, e.g., a 3D spatial image. In someembodiments, the 3D representation is generated as a 3D image floatingin space, hence, referred to as a 3D spatial image. The opticalcomponent can generate the 3D spatial image from a 2D content based onchromatic aberrations. In some embodiments, chromatic aberrations are adefect or a problem in an optical component, e.g., a lens, that occurswhen a lens is either unable to bring all wavelengths of color to thesame focal plane, and/or when wavelengths of color are focused atdifferent positions in the focal plane. For example, in a given colorsequence such as RGB, the red color focuses farthest from the lens, bluefocuses closest to the lens and green focuses between red and blue. The3D imaging system exploits the optical effect of the chromaticaberrations to focus light of varying wavelengths/colors from the 2Dcontent at different points in space to generate the 3D spatial imagefrom the 2D content. In some embodiments, to have specific portions inthe 2D content formed at specified depths in the 3D spatial image, the2D content is color encoded with appropriate colors. The 3D imagingsystem includes a content generator that generates color-encoded 2Dcontent. The image source displaying the 2D color-encoded image isviewed through the optical component, which focuses the color encodedspatial images at different points in visual space.

The 3D imaging system can be implemented in various configurations. In afirst configuration, referred to as “aerial viewing configuration,” theoptical component includes a pair of lenses, e.g., a pair of Fresnellenses, which receives the color-encoded 2D content from an image sourceon one side of the pair of lenses and generates a 3D representation ofthe 2D content on the other side of the pair of lenses in a spacebetween a viewer and the pair of lenses. The 3D spatial image appears tofloat in the space between the viewer and the pair of lenses. Theoptical component focuses the light of varying wavelengths from the 2Dcontent at different points in space, in free space between the viewerand a “viewing window.” The light of varying wavelengths, in the aerialviewing configuration, is focused at different points in real space toprovide a perception of the 3D spatial image. The viewer can view the 3Dspatial image without any user-worn apparatus, e.g., 3D glasses.

In a second configuration, referred to as “infinity viewingconfiguration,” the optical component includes a single lens, e.g., aFresnel lens, that receives the color-encoded 2D content from an imagesource on one side of the lens and generates a 3D representation of the2D content on the same side of the lens. The 3D spatial image appears tobe a magnified version of the 2D content and the background portionappears to be generated at or near optical infinity. The opticalcomponent focuses the light of varying wavelengths at different pointsin virtual image space, behind a “viewing window,” which the viewerperceives as the 3D spatial image. The light of varying wavelengths, inthe infinity viewing configuration like the aerial viewingconfiguration, is focused at different points in virtual image space.

The depth of the 3D spatial image, e.g., depth between specific portionsof the 3D spatial image, can be controlled based on various factors,e.g., using specific colors for specific portions. For example, forbackground imagery (imagery which is formed farthest from the viewer), acombination of dark blue and black is typically used, and red color isused for foreground imagery, e.g., a portion of the imagery that is tobe formed the nearest to the user. The use of dark blue and black isgenerally preferred of the sole use of dark blue, as the combination ofdark blue and black adds texture and depth to most spatial scenes.

The spatial imagery produced by both viewing configurations may havepseudo-motion parallax. In some embodiments, motion parallax is a typeof depth perception cue in which objects that are closer appear to movefaster than objects that are farther. As the color red appears to befocused more forwardly than green or blue, when an observer movesposition, the red components shift more rapidly than the green or bluecomponents, and the green components likewise shift more rapidly thanblue components. This may sometimes be perceived as a kind ofpseudo-motion-parallax depending on content.

In both viewing configurations the spatial images are color encoded into2D images and displayed on an image source, e.g., an electronic 2Ddisplay such as light emitting diode (LED) or liquid crystal display(LCD) monitors, plasma displays or alternatively by projection onto a 2Dscreen with digital light processing (DLP) projectors, lasers. The imagedisplayed on the image source can be any 2D image, e.g., a static imageor a dynamic image. The 2D image can be computer generated imagery(CGI), or images of real-world objects, or a combination. The 2D imagecan be color-encoded using various techniques, e.g., using 3D imagingsoftware implemented in a content-generation system.

In the real world, the depth cues of convergence and accommodation areconsistent and the convergence and accommodation mechanisms are linkedtogether. Accommodation or re-focusing of the eye is required whenmoving from one object to the other. The eyes constantly refocus onnearer and farther objects in a real scene. In typical stereoscopic orautostereoscopic imaging systems, as an object gets farther from theplane of the screen or display, in front or behind, the convergence ofthe eyes change, but unlike the natural world, accommodation stays thesame, since all image information is on one plane. The farther away fromthe image plane (screen or display) an object is, the larger thediscrepancy between accommodation and convergence will be.

In typical stereoscopic or autostereoscopic imaging systems, convergenceand accommodation stimuli are not linked, which can lead to visualconflicts and observer discomfort. The disclosed embodiments reduce oreliminate conflicts between accommodation and convergence by focusingdifferent images at different depth locations in space. Correlationbetween accommodation and convergence allow the observer to focus atdifferent depths within a 3D spatial scene, for extremely naturalspatial viewing experience. Thus, the disclosed embodiments provideimproved spatial imaging systems.

The 3D imaging system includes visual perceptual enhancements, which canbe functional in nature, to provide a viewer with an enhanced spatialviewing experience, e.g., elimination of “flatness cues” and addition ofenvironmental cues. In some embodiments, flatness cues are visual cues,which allow a viewer to determine whether or not a surface or an imageis flat, and environmental cues are cues which relate the syntheticspatial imagery to the real world environment in which the viewerexists. These enhancements can optimize spatial perception of theimagery and greatly improve the perceived spatial visual experience.Examples of such enhancements include a mask system, visible referenceobjects, silhouettes, shadows of light and synthetic illumination. Thesevisual perceptual enhancements can eliminate the flatness cues andreinforce the imagery's placement in the real-world space. The spatialimagery, which is focused at actual different points in a physical orvirtual image space, is further enhanced by monoscopic depth cues/2Dcues, which work in cooperation with the elimination of flatness cuesand the addition of environmental cues. The differences in the visualpresentation of spatial imagery in both the aerial viewing and theinfinity viewing configurations may have be taken into considerationwhen designing or selecting the mask system and environmental cues foreach viewing configuration.

Unlike a volumetric display, both viewing configurations do not placeactual “voxels” of light at precise or specific points in space. In someembodiments, a voxel represents a value on a regular grid in 3D space.As with pixels in a bitmap, voxels themselves do not typically havetheir position, e.g., coordinates, explicitly encoded along with theirvalues. Instead, the position of a voxel is inferred based upon itsposition relative to other voxels. However, many additional factorsbeyond where light is focused at various points in space contribute tothe spatial perception of the imagery. These additional factors may becontrolled in a manner, which will allow the observer to perceive thespatial imagery as deeper than the actual volume of depth in space thefocused spatial imagery actually spans. The disclosed embodiments maynot place actual voxels of light at precise or specific points in space.

The disclosed 3D imaging system can be used in various applications,e.g., art, entertainment, movies, video games, ornamental design,ambient lighting installations, special attractions, haunted houses,psychedelic light-shows, scientific visualization.

The 3D spatial image may be additionally enhanced with non-visualcontent, non-visual cues, and observer interaction techniques, e.g., byuse of multi-channel spatial audio systems, synchronization with sound,motion sensors, human interface devices, tactile transducers, andreal-time interaction.

Turning now to the figures, FIG. 1 is a block diagram of an example 100illustrating chromatic aberration phenomenon of an optical component,consistent with various embodiments. The optical component 105 can be anoptical component, e.g., an optical lens, that can be used in thedisclosed 3D imaging system. As described above, chromatic aberration isan optical phenomenon in which the optical component is unable to focusall wavelengths to the same focal plane and instead focuses them atdifferent focal planes. In the example 100, the optical component 105focuses different wavelengths of light 110, e.g., colors, from an imagesource (not illustrated) at different focal planes. For example, the redcolor focuses farthest from the optical component 105 at a first focalplane 125, the blue color focuses closest to the optical component 105at a second focal plane 115, and the green color focuses at a thirdfocal plane 120 between the focal planes of red and blue. The 3D imagingsystem exploits the optical effect of the chromatic aberration to focuslight of varying wavelengths/colors from the 2D content at differentpoints in space, thereby giving a perception of depth in the generated3D spatial image. The 3D imaging system uses the chromatic aberrationphenomenon in both the viewing configurations.

FIG. 2 is a block diagram of an aerial viewing configuration of the 3Dimaging system, consistent with various embodiments. In the aerialviewing configuration 200, the 3D imaging system includes an opticalcomponent 205 that generates a 3D spatial image from a 2D color-encodedcontent displayed by an image source 210. In some embodiments, theoptical component 205 is similar to the optical component 105, e.g.,exhibits the chromatic aberrations as described with reference to theoptical component 105. The optical component 205 can be constructedusing a pair of lenses (also referred to as a “lens doublet” 205), e.g.,a pair of Fresnel lenses. In some embodiments, a Fresnel lens is a typeof compact lens that has a large aperture and short focal length withoutthe mass and volume of material that would be required by a lens ofconventional design. A Fresnel lens can be made much thinner than acomparable conventional lens, in some cases taking the form of a flatsheet.

The lens doublet 205 includes two Fresnel Lenses, e.g., a first Fresnellens 206 (“L1”) and a second Fresnel lens 207 (“L2”), that are spacedapart and with their individual concentric grooves mutually facing eachother. The lens doublet 205 receives light corresponding to a 2D imagefrom an image source 210 on one side of the lens doublet 205 andgenerates or forms a 3D spatial image 235 of the 2D image on the otherside of the lens doublet 205. The lens doublet 205 forms the 3D spatialimage 235 in a space between the lens doublet 205 and a viewer 240.Since separate colors such as red, green, and blue have differentwavelengths of light and because of the chromatic aberration of the lensdoublet 205 the different colors cannot be focused at a single commonpoint in the focal plane due to different refractive indices of the lensdoublet. Different portions of the 3D spatial image 235 are formed atdifferent distances from the lens doublet 205 based on the color of thecorresponding portions, e.g., sorted by wavelength. For example, thelens doublet 205 focuses a portion of the 3D spatial image 235 that isof red color farthest from the lens doublet 205 (and nearest to theviewer 240) at a red focal plane 225, focuses the portion that is ofblue color closest to the lens doublet 205 (and farthest to the viewer240) at a blue focal plane 215, and focuses the portion that is of greencolor at a green focal plane 220, which is between the red and bluefocal planes. The difference in distances between these various portionsgives a perception of depth between these portions and hence, theperception of a 3D image.

Note that the above illustration of generation of a 3D spatial imageusing only a RGB color sequence is just an example. The color sequenceof the 3D spatial image is not limited to the above color sequence; thecolor sequence can include various other colors, gradients of colors,hues of colors, etc., and each of the colors are focused at theirappropriate focal planes.

The image source 210 is typically a device that is capable displaying acolor-encoded 2D image, e.g., moving content, still content, or acombination. The image source can be an electronic 2D display such asLED or LCD monitors, plasma displays or alternatively by projection ontoa 2D screen with DLP projectors, and lasers. The 2D image can becolor-encoded using various techniques, e.g., using 3D imaging software.In some embodiments, the far background is a typically a mixture of darkblue and black textures, objects in the middle of the scene are green,and objects that are spatially formed in the front are red.

FIG. 3 is an example 3D spatial image generated by the 3D imaging systemin the aerial viewing configuration of FIG. 2, consistent with variousembodiments. In the example 3D spatial image 300, the blue background305 is focused farthest from a viewer, e.g., the viewer 240, thered/orange portion 315 is focused closest to the viewer 240 and thegreen object 310 is focused between the red and the blue objects.

FIG. 4 is another example 3D spatial image generated by the 3D imagingsystem in the aerial viewing configuration 200 of FIG. 2, consistentwith various embodiments. Again, various colors of the 3D spatial image400 are formed at various distances from the viewer 240.

Referring back to the lens doublet 205 in the aerial viewingconfiguration 200, an f-number (f-stop) of a lens is the ratio of thelens's focal length to an aperture of the lens. In some embodiments, thelenses L1 and L2 have an identical f-number or an f-number within aspecified range. For example, the lenses L1 and L2 each have an f-numberof 1. In some embodiments, the focal length of each of the lenses isequal to the effective aperture thereof. In some embodiments, thef-number of each of the lenses L1 and L2 is between 1.5 and 0.5. With anf-number higher than 1.5, the generated 3D spatial image 235 can becomeblurry and with an f-number lower than 0.5, the manufacturing of thelens can be difficult, and an actual image can get projected instead offorming a 3D spatial image.

In some embodiments, the Fresnel lens grooves are preferred to have apitch of about 0.5 mm. Although smaller pitches are available, forexample, to about 0.05 mm, the integrity of the grooves appears tosuffer with such smaller pitches. For additional consideration whenselecting Fresnel lens, Fresnel lenses may be configured in positive ornegative relief. With positive relief Fresnel lenses, the grooves extendabove the level of the starting outer surface of the acrylic materialfrom which they are formed. With negative relief, Fresnel lenses thegrooves extend below the surface of the acrylic material. Positiverelief Fresnel lenses are used in the opposite orientation sense asnegative relief Fresnel lenses. In some embodiments, it is preferred touse positive relief Fresnel lenses.

A lens has an imaginary point referred to as the 2 F point, which istwice the focal length. An image source placed at approximately 2 F onone side of a lens causes a real-image to form in space at approximately2 F on the other side of the lens. The exact location of the lens can beselected to increase or decrease the size and in addition to changingplacement of the “floating” image. The lens doublet 205 is placed at aspecified distance from the image source 210, e.g., at a distance D1from the image source 210 to the lens L1. The lenses L1 and L2 arespaced apart by a distance D2 and with their grooves facing each other.The “real-image” is focused in front of Lens L2 at a focal plane D3 (notillustrated) assuming there is only one focal plane in an idealsituation. However, the real-image is generated as a 3D spatial imageand therefore, has smoothly varying depth over various focal planes. Insome embodiments, the distance D1 is between two to three times thefocal length of the lens doublet 205. This produces a reduced-in-sizereal-Image floating in front of the lens L2, and due to the chromaticaberrations, the image focused at location D3 in front of the lens L2 isnot planar but spatial in nature. By varying D1, the distance D3 atwhich the 3D spatial image floats from the lens L2 varies. For example,decreasing D1, by moving the lens doublet 205 closer to the image source210, increases the distance D3. Likewise, increasing the distance D1, bymoving the lens doublet 205 farther from the image source 210, decreasesthe distance D3.

In some embodiments, varying D1 also changes the size of the 3D spatialImage 235. For example, an increase of distance D1 can result in thedecrease of the size of the 3D spatial image 235 at the distance D3,whereas a decrease in the distance D1 can lead to the magnification ofthe 3D spatial image 235 at the distance D3. Therefore, as D1 isdecreased the 3D spatial image 235 is both magnified and moves closer tothe observer, farther from the lens L2 and as D1 is increased, the 3Dspatial image 235 is both reduced in size and moves away from the viewer240 and closer to the lens L2. As stated earlier, D1 is preferablybetween two to three times the focal length of the lens doublet 205.This can produce a reduced-in-size real-image floating in front of thelens L2. When D1 is lower than 2 F (twice the focal length) of the lensdoublet 205, a magnified-in-size real-image floats in front of the lensL2. For some cases, D1 may be reduced as low as 1.5 times the focallength of the lens doublet 205. The spacing D2 between the lenses L1 andL2 can typically be equal to or less than three-quarters the focallength of each one of the Fresnel lenses forming the lens doublet 205.The distance D2 can also be selected as large enough to avoid the moiréfringe effects with the floating 3D spatial image 235. In someembodiments, the distance D2 maintains a range in which there areintentional chromatic aberrations of images.

As mentioned above, the two lenses 206 and 207 together act as a singleoptical element. Each of the Fresnel lenses exhibits an f-number andfocal length. However, acting as a doublet, the f-number can change, forexample, to one-half that of the individual Fresnel lenses. In someembodiments, the size of the aperture of the lens doublet 205 should besmaller than the corresponding dimension of the image source 210. Theimage source is preferably at least 1.5 times the size of the Fresnellenses. The specific size of the image source selected depends onvarious factors such as D1 and design of visual peripheral area, etc. Insome cases, depending on content and desired visual effect, it may bedesirable to tilt one or more of the Fresnel lenses. Tilting one or moreof the Fresnel lenses may add to the spatial nature of certain content.

In some embodiments, changing a size of an image element within the 2Dimage content, along with changing wavelength, changes the apparentdepth of the image element. In optical terms, the image focused in frontof the lens L2 is a real-image. The 2D image on the image source 210 isinverted as it passes through the lens doublet 205 and projected as areal-image. The inverted image (3D spatial image 235) viewed in front ofthe lens L2 appears to be floating in free space. To compensate for thisinversion and correctly display this image as intended, the spectrallyencoded 2D image on the image source 210 is inverted in relation to itsintended viewing orientation, as to be correctly displayed when viewedas the floating real-image (3D spatial image 235). Since the foremostportions of the 3D spatial image 235 float in free space in front of theviewing window, e. g., in the space between the optical component L2 andthe viewer 240, window violations occur when a visual element moves offthe outer side of the viewing window, eliminating the appearance thatthe imagery is floating. The bounding of foremost images may be appliedto the aerial viewing configuration 200, to prevent window violations.Foremost image elements may be bound so they may not enter and exit fromthe viewing window to the sides, top or bottom of the viewing window.Image elements farthest from the viewer 240 and the dark blue/blackbackground, typically appearing behind the viewing window and thereforenot susceptible to window violations, do not need such bounding.

FIG. 5 is a block diagram of a mask system used with the aerial viewingconfiguration of the 3D imaging system, consistent with variousembodiments. The aerial viewing embodiment 200 of FIG. 2 can use a masksystem 500 for enhancing the spatial perception of the 3D spatial image235. The mask system includes a first mask M1 505 and a second mask M2515. The masks can be used to reduce the flatness cues. The front of themask, e.g., of mask M1, can function as a cover for the lens doublet205. The mask M1 includes an aperture or an opening 510 and the mask M2includes an opening 520 through which light from the image source 210passes out of the lens doublet 205. The mask M1 is placed so that theedges of the opening 510 cover the edge of the lens L2, that is, theFresnel lens closest to the viewer 240. The mask M2 is placed in frontof the mask M1 and towards the viewer 240 with a gap G1 605 between maskM1 and mask M2, e.g., a gap of few inches, which is illustrated at leastwith reference to FIG. 6.

FIG. 6 is a top view of the aerial viewing configuration of the 3Dimaging system, consistent with various embodiments. The gap G1 605helps dislocate the flat plane of the lens L2 in the mind of the viewer240, that is, reducing flatness cues. The smaller size of the apertureof mask M2 compared to the aperture of Mask M1 also allows differentparts of the peripheral background of the 3D spatial image 235 to comein and out of the view, as the view or the viewer 240 moves. Thisenhances the spatial realism of the display. The size of the gap G1 605can vary based on various factors, e.g., based on the size of the imagesource 210, size of the lens doublet 205, distance D1, visual contentbeing displayed, desired visual effect. In some embodiments, the mask M2typically is a wall with a window through which 3D spatial images areprojected outward. The aperture on the mask M2 is slightly smaller thanthe aperture on rear mask M1.

The openings can be of any shape, e.g., rectangular, ellipsoid, anirregular border pattern, hexagonal, depending on shape of the viewingwindow on the wall on which the mask and the lens doublet 205 isinstalled. The opening 510 may be of one shape and the opening 520 maybe of a different shape. In some embodiments, the edges of front mask M2may be made of a gradated material varying from transparent to opaque,specifically with the opaque area covering the outer side edges of themask M2, in a manner which allows the gradated transparency area becomemore transparent towards the center of the viewing window.

The masks may be made of any suitable material, e.g., wood, acrylic,foam core. The masks can be of any color and finish. For example, themasks can be black and have a matte finish. In some embodiments, themask M2 color finish can match with the wall at which the 3D imagingsystem is installed. In some embodiments, a visible reference object 610such as a picture frame, drapes, a window frame, and a door frame, mayalso be placed in front of the aperture on Mask M2, near the projectedfloating spatial image. The visible reference object 610 can helpestablish a distance between the viewer 240 and the projected 3D spatialimage.

In some embodiments, a visible reference object 610 is a physical objectplaced at or near the frontal region of the 3D spatial image 235 that isclosest to the viewer 240. In the aerial viewing configuration, thevisible reference object 610 can be placed approximately at the frontalprojected point of the 3D spatial image 235. However, in someembodiments, depending on content and application, the visible referenceobject 610 may be as near as possible, slightly in front of or slightlybehind the foremost projected portion of the 3D spatial image 235 (suchas the red focal plane) in relation to the viewer 240. The visiblereference object 610 will not usually overlap with the generated 3Dspatial imagery, unless the also functioning as a silhouette, howevermotion parallax between the spatial imagery and the visible referenceobject 610 will occur without occlusion. In the case of the aerialviewing configuration, the motion parallax can help enhance theimpression the floating spatial imagery exists within the sameenvironment as the viewer 240.

FIG. 7 is an example 700 of an artist's rendition of a viewing settingfor the aerial viewing configuration, consistent with variousembodiments. In the example 700, a picture frame 705 mounted on a wallis used as a visible reference for the lens doublet 710 installed in thewall. In some embodiments, the lens doublet 710 is similar to the lensdoublet 205 of FIG. 2. The wall can also act as the front mask M, andthe opening in the wall as an aperture through which the 3D spatialimage is projected.

FIG. 8 is another example 800 of a viewing setting for the aerialviewing configuration, consistent with various embodiments. In theexample 800, the doors in a miniature model house act as a visiblereference and the opening around the door acts as an aperture. Theextended open doors and the doorframe around the aperture openingclearly establishes the distance from the skeleton to the viewer.

In some embodiments, silhouettes are physical objects which addreal-world occlusion and motion parallax from the observer's environmentto the 3D spatial imagery, enhancing spatial impression by working inconjunction with the window parallax and pseudo-motion-parallax. Asilhouette can make use of a psychological vision cue known as occlusion(interposition), which means that portions of a more distant object maybe obscured by objects in the foreground. Additionally, a silhouette canmake use of a physical cue known as motion parallax, where movement ofthe observer allows them to view different portions of athree-dimensional scene. A silhouette is also capable of exhibitingmotion parallax and occlusion in a plurality of directions when used incombination with the 3D spatial image.

Occlusion is a psychological depth due, which is typically alreadypresent in the within the spatial image, as visual elements focused atdifferent depths within a scene often overlap and therefore, occlude thevisual element which is behind them in relation to the observer. Motionparallax is a physical cue associated with real 3D scenes which impartsto the brain the perception that a viewed scene is indeed 3D. When theobserver moves from side to side (up and down too, as with head motion),the silhouette can offer significant motion parallax and occlusion inrelation to the 3D spatial image, enhancing the depth, and overalldimensionality of the real-image illusion.

If properly placed, a silhouette may also function as a visiblereference, as described earlier. In many cases, the silhouette alsofunctions as a visible reference, typically when the size, shape andplacement of a silhouette allows a specific area of the silhouette to beplaced near the front focal plane of the spatial image, e.g., a focalplane closest to the viewer. More specifically, a specific area of thesilhouette is to be placed near the front focal plane of the spatialimage to function as a visible reference.

A silhouette can function as an environmental cue adding visual overlap,occlusion and observer motion parallax effects from the viewer'senvironment over the synthetic spatial imagery. The 3D spatial image 235may be made to appear more realistic if certain visual features appearto match the surrounding environment. The 3D spatial image 235 emitslight which may be cast onto the surface of a silhouette or the visiblereference object 610. The light which is cast onto a silhouette orvisible reference object 610, referred to as shadows of light, mayappear to follow the motion of a visual element within a 3D spatialimage in a manner similar to an actual shadow.

A silhouette may be any device that affects the transmission of lightfrom the spatial scene to the observer, and may be opaque, reflective,translucent, clouded, or transparent with reflectivity, color, tint,pattern, distortion, and/or any combination thereof. A silhouette mayhave any shape; and be positioned by any means, such as by attachment tothe wall, or by suspension in position independent of the wall, placedon a pedestal, fixedly or adjustably with respect to distance from theobserver's eyes and/or the extent of the obstruction of the observer'sview. A silhouette, however, should be shaped to be visible againstparts of the spatial scene being viewed. A silhouette should be furthershaped to allow the desired amount of visibility of the spatial scenebeing viewed in combination with the silhouette. A silhouette willgenerally have visual features which will continually overlap andun-overlap with the spatial imagery behind them, the visuallyoverlapping features can be opaque, transparent or semi-transparent.

FIG. 9 is an example of a silhouette used in the aerial viewingconfiguration, consistent with various embodiments. The picture 900depicts a silhouette, e.g., a paper lantern. As described above,silhouette adds occlusion and motion parallax cues, blocks outer edgesof the lens and serves as the visible reference for floating imagery.The picture 905 illustrates the floating spatial image viewed withinSilhouette. The tears in the paper lantern add occlusion and motionparallax cues, and the front lantern hole acts as a the visiblereference. The semi-transparent material of the paper lantern addsadditional occlusion and motion parallax cues. In some embodiments, aspecific type of the paper lantern, e.g., size, is a combination of D1,the size of the floating 3D spatial image and other such relatedfactors.

FIG. 10A is a block diagram an infinity viewing configuration of the 3Dimaging system, consistent with various embodiments. In the infinityviewing configuration 1000, the 3D imaging system includes a singleoptical component 1005, e.g., a Fresnel Lens (“L3”), that receives lightcorresponding to a 2D image from an image source 1010 placed on one sideof the lens L3 and generates a 3D spatial image 1015, which isillustrated in FIG. 10B, on the same side of the lens L3. If the lens L3is installed on a wall, then the position in the wall at which the lensL3 is installed can act as a viewing window 1035, and the 3D spatialimage 1015 is formed right behind the viewing window 1035. In theinfinity viewing configuration 1000, the 3D spatial image 1015 does notfloat in free space in front of the viewing window between the opticalcomponent 1005 and the viewer 1020 as with the aerial viewingconfiguration 200.

However, in the infinity viewing configuration 1000 can produce 3Dspatial images at a much greater distance than the aerial viewingconfiguration, in terms of images in the spatial scene spanning fromgreat distances away from the viewer 1020 to very close to the viewer1020 (up until the lens L3). The infinity viewing configuration also hasa much larger field of view than the aerial viewing configuration 200,due to which the viewer 1020 has more freedom to change his/her positionin viewing the 3D spatial image 1015. Since the spatial imagery does notfloat in free space in front of the viewing window 1035, e.g., in thespace between the optical component L3 and the viewer 1020 as with theaerial viewing embodiment, window violations do not occur when a visualelement moves off the outer side edges of the viewing window 1035.Therefore, there is more freedom of movement for specific visualelements in the 2D image from the image source, when producing 2Dcontent for the infinity viewing configuration 1000.

With the aerial viewing configuration 200, chromatic aberrations causedifferently colored elements of the 3D spatial image 235 to focus atdifferent points in space. With the infinity viewing configuration 1000,light does not focus behind the lens L3 in the same manner.Specifically, the virtual-image produced by the infinity viewingconfiguration 1000, may appear to be focused at between the lens L3 andoptical infinity, as illustrated in FIG. 10A. FIG. 10A is a top view ofthe infinity viewing configuration of the 3D imaging system, consistentwith various embodiments. In some embodiments, the image source 1010 issimilar to the image source 210 of FIG. 2. The image source 1010 has acolor-encoded 2D image, but with more flexibility for moving the frontand middle imagery off to the side of the viewing window 1035. This isbecause the 3D spatial image 1015 is viewed as a virtual-image. The 3Dspatial image 1015 in the infinity viewing configuration 1000 is viewedas if looking out a window, with all imagery behind the window.

The lens L3 is placed in front of the image source 1010 at a distanceD4. In some embodiments, D4 is approximately the focal length of lensL3, or slightly lesser. The specific placement can depend on visualcontent and optical effect desired. The lens L3 can produce a backgroundimage, e.g., a background portion of the 3D spatial image 1015 at ornear optical infinity, when then image source 1010 is viewed through thelens L3. In some embodiments, the size of the lens L3 should be smallerthan the corresponding dimension of the image source 1010. The imagesource 1010 is preferably at least 1.5 times the size of the lens L3.The specific size of the image source selected depends on variousfactors such as D4 and design of visual peripheral area, etc. The focallength of the lens L3 can be between F 1.5 and F 0.5. The grooves of thelens L3 have a specified pitch, e.g., 0.5 mm. The lens L3 is mounted ona mask M3 1025, which can be similar to the masks M1 or M2 of FIG. 2,with an aperture slightly smaller than the lens L3, e.g., just coveringthe edges of lens L3. Typically, a visual reference object 1030, such asa picture frame or a window frame can cover the outer edges of lens L3.

When the image source 1010 is viewed through the lens L3, the imagesource 1010 is magnified and appears to be at a distance much greaterthan it actually is. For example, the image source 1010 appears to be ata distance D5 from the lens L3. That is, the apparent image source 1011is at the distance D5 and is a magnified version of the image source1010.

As with the aerial viewing configuration 200, different color portionsof the 2D image focuses at different distances from the lens L3. Forexample, as depicted in 3D spatial image 1015, red focuses the closestto the viewer 1020, green in the middle and dark blue mixed with blackis the far background. Unlike the aerial viewing configuration 200,which produces a real-image floating in front of the lens doublet 205 ofFIG. 2 and the viewing window 1035, the image viewed though lens L3 is,in optical terms, a virtual-image, appearing behind the viewing window1035. This allows imagery to appear at apparent distances betweenseveral feet away from the viewer 1020 to a larger distance from theviewer 1020.

Also, unlike the aerial viewing configuration 200, the 2D color-encodedimage on the image source 1010 for the infinity viewing configuration1000 may not have to be inverted, as it appears upright (uninverted)when viewed though lens L3. The background and image elements recedinginto the far distance can be perceived as if they are at or near opticalinfinity. Perceived distance depends on how close to the focal length ofthe lens L3 the image source 1010 is. The distance D4 can be varied tosuit different content and desired effects. When the image source 1010is too far past the focal length, the image can distort or degrade. Insome embodiments, the image source 1010 is placed at the focal point ofthe lens L3 or slightly closer than the focal point. This can opticallyplace the background portion of the 3D spatial image 1015 at or nearoptical infinity.

If an image source 1010 is placed at a distance D4 less than the focallength of the lens L3, the viewer 1020 will perceive that image to becloser than at infinity. Typically, the image source 1010 is to beplaced at a distance D4 to the lens, no closer than 65% of the focallength. In a manner similar to the aerial viewing configuration 200,placing the image source 1010 at various distances relative to the focallength, due to chromatic aberrations, different wavelengths will appearat varying depths. The 3D spatial image 1015 can be formed right behindthe viewing window 1035 but not float in free space between the viewingwindow 1035 and the viewer 1020.

As with the aerial viewing configuration 200, changing a size of animage element within a scene in the 2D content, along with changing thewavelength can change apparent depth. However, the infinity viewingconfiguration 1000 is capable of producing images at a much greaterdistance from the viewer 1020 than the aerial viewing configuration 200.Since the 3D spatial image 1015 in the infinity viewing configuration1000 does not appear at a depth closer to the viewer 1020 than theviewing window 1035, the bounding of foremost images as applied to theaerial viewing configuration 200, may not be applied. Images may enterand exit from the viewing window 1035 to the sides, top or bottom of theviewing window 1035 without causing any reduction in the spatialperception of the 3D spatial image 1015.

In some cases, depending on 2D content and desired visual effect, it maybe desirable to tilt the lens L3. Tilting the lens L3, may add to thespatial nature of certain content. In some embodiments, due to the extraperipheral imagery, the dark blue/black background in the 2D imagedisplayed on the image source 1010 surrounds the middle and frontalobjects more than is viewed when looking through the viewing window1035. More or less of the background come into and out of view throughthe window as the viewer 1020 moves. The same thing happens when lookingout a real window, due to parallax by observer motion, which is referredto as window parallax. This adds to the spatial realism of the display.The viewing window 1035 also hides the edges of the background, so thereis no abrupt change at the edges. Perceived spatial depth is enhancedbecause the background appears to continue indefinitely behind the sideedges of the viewing window 1035.

Referring to FIG. 10B, the viewer 1020 stands in front of the viewingwindow 1035 seeing red objects just on the other side of the viewingwindow 1035, green in the middle, and blue/black in the far distance.The Blue/Black background can be perceived as extremely distant, e.g.,many miles. This is because the background imagery is collimated orquasi-collimated and appears at or near optical infinity. Thecircumferential peripheral area is out of the observer's sight whenlooking at the viewing window 1035 in the center. As the viewer 1020moves, more or less of the peripheral scene comes in and out of view,just as if looking out a real window, e.g., as illustrated in FIG. 10C.FIG. 10C is another top view of the infinity viewing configurationillustrating window parallax phenomenon, consistent with variousembodiments. In the FIG. 10C, the circumferential peripheral area comesinto the view as the viewer 1020 moves.

FIG. 11A is a picture of an example viewing setting of the infinityviewing configuration of the 3D imaging system, consistent with variousembodiments. In the example view setting of FIG. 11A, the opticalcomponent, e.g., Fresnel lens L3, is mounted on a wall with the groovesfacing the viewer. The edges of the lens L3 is covered with a pictureframe, which acts as a visual reference object. The image source isbehind the wall. FIG. 11B is a picture of a 3D spatial image generatedby the infinity viewing configuration of the 3D imaging system of FIG.11A, consistent with various embodiments.

The 3D imaging system, either in the aerial viewing configuration 200 orthe infinity viewing configuration 1000, generate 3D spatial images ofthe color-encoded 2D images from an image source. To place the images toat varying apparent depths, the 2D images displayed on the image sourceneed to be encoded with spatial information. Color/wavelength encodesthe apparent distance to the observer. The following paragraphs describegeneration of the color-encoded 2D content.

FIG. 12 is a block diagram of an environment in which the disclosedembodiments can be implemented, consistent with various embodiments. Theenvironment 1200 includes a content-generation system 1205 that is usedto generate 2D color-encoded content 1220, and a 3D imaging system 1210that is used to generate a 3D spatial image 1225 from the color-encodedcontent 1220. In some embodiments, the 2D color-encoded content 1220 issimilar to 2D color encoded content used in the aerial viewingconfiguration 200 of FIG. 2 and in the infinity viewing configuration1000 of FIGS. 10A and 10B. The content-generation system 1205 cangenerate the 2D color-encoded content 1220 from source content 1215,e.g., images or videos captured using various input devices such ascameras. In some embodiments, a user, e.g., content creator, candirectly generate the 2D color-encoded content 1220 using CGI techniquesin the content-generation system 1205. In some embodiments, thecontent-generation system 1205 can generate the 2D color-encoded content1220 based on a combination of the CGI and source content 1215. Layeredcomposite imagery in conjunction with wavelength/color dependent spatialencoding can provide control over spatial perception of local visualfeatures of images and objects within a 3D scene viewed as a spatialimage. The content-generation system 1205 can implement a 3D modelingsoftware or other custom computer code to create a 3D scene or any otherform of the 2D color-encoded content 1220. A 3D scene can consist ofimages, data representing 3D models, data such as lighting and fogeffects data, shader code etc. A 3D scene can also be scene capturedwith a camera, capture device or sensor, (e.g., Kinect from Microsoft orLytro from Lytro) which also provides depth information. A perspectiveof the 3D scene is rendered as a 2D color-encoded content 1220 to beviewed as a 3D spatial image 1225.

The source content 1215 may or may not include depth information, e.g.,z co-ordinates on a 3D scale (x, y, z). If the source content 1215includes the depth information, then the content-generation system 1205can automatically analyze the source content 1215 and encode thespecific portions of the source content 1215 with specific colors basedon the depth information of the specific portions to generate the 2Dcolor-encoded content 1220. As described earlier, for both viewingconfigurations, different portions of a spatial image appear to befocused at different points in space due to chromatic aberrations of theoptical component, e.g., Fresnel Lenses. For example, red image elementsappear in the front, green image elements appear in the middle, and blueimage elements appear in the background. Accordingly, thecontent-generation system 1205 can encode portions of the source content1215 that are to be formed in the foreground or closest to a viewer1230, e.g., that has least depth among other portions, with red,portions that are to appear in the far background from the viewer 1230,e.g., portions that have largest depth, with blue, and encode portionsthat are to appear in between the background and the foreground, e.g.,with depth between that of the portions of foreground and background,with green.

In embodiments where the source content 1215 does not include the depthinformation, a user can access the source content 1215, e.g., using animage processing software implemented by the content-generation system1205 and assign a color to one or more portions of the source content1215 according to relative distances the portions have to be formed inthe 3D spatial image 1225.

When the 2D color-encoded content 1220 is imaged using the 3D imagingsystem 1210, the 2D color-encoded content 1220 is generated as a 3Dspatial image 1225 in which different portions of the source content1215 are formed at different distances from the viewer 1230, therebyproviding a perception of the depth in the generated 3D spatial image1225. The 3D imaging system 1210 can be implemented in the aerialviewing configuration 200 or the infinity viewing configuration 1000. Atthe minimum, the 3D imaging system 1210 has at least one opticalcomponent, e.g., a Fresnel lens such as L1, L2 or L3. The 3D imagingsystem 1210 can also have an image source, e.g., image source 210 or1010, which displays the 2D color-encoded content 1220. The 3D imagingsystem 1210 can also have a mask system, a visual reference, asilhouette etc.

Note that the RGB color sequence used for encoding the source content isjust for illustration purposes. Various other color sequences can beused for encoding the source content to encode the apparent distance tothe viewer 1230. In some embodiments, various other factors associatedwith the source content can also be varied to change the apparentdistance. For example, by varying the hue in conjunction with x, yplacement, size, shading, luminance, and various monoscopic depth cuesof the portions of the source content, the portions of the sourcecontent can be placed anywhere in a spatial scene. Similarly, bymodifying hue, luminance, shading, contour, edge outlines, and othermonoscopic depth cues, over the surface of an individual object in aspatial scene, the object can have individual parts of it focused atdifferent points in space, closer or farther from the viewer 1230.

The above can be accomplished through the content-generation systeminvolving linear color gradients, color ramps, graphics shaders, imagescaling, image rotation, (x, y) image placement, layered imagecompositions, image transparency, alpha composting, image colorizationand motion paths, in addition to other image processing techniques. Inaddition to hue/color and luminance, forced perspective techniques and2D Depth cues such as relative size, shading and shadows may also encodedepth information onto the encoded image. In some embodiments,generation and control of 2D depth cues are typically provided byvarious computer graphics modeling and rendering applications. In someembodiments, the content-generation system 1205 includes a shader toolthat is used to shade an image, produce special effects, add levels ofcolor to an image or do video post-processing. The shader tool may beprogrammed to shade the source content according to distance from a realor virtual camera, e.g., which can be provided as depth information bythe real or virtual camera. In some embodiments, the content-generationsystem 1205 implements a colorizer tool that is used to add colorinformation to image elements, which allows spatial encoding of the 2Dimage with wavelength/color encoded spatial information. The colorizertool can be used in addition to or as an alternative to the shader toolto colorize the object.

In some embodiments, the content-generation system 1205 provides thecontent creator with depth information, e.g., information regardingdistance from a virtual camera to objects within a virtual scene, and/orderives the depth information, e.g., information regarding distance froma real camera to objects within a real scene, based on the informationprovided by the image capture devices, e.g., Kinect or Lytro, used tocapture the source content 1215.

Typically, in 3D computer graphics, a depth map (also known a as a“z-map”) is an image or image channel that contains information relatingto the distance of the surfaces of scene objects from a viewpoint. Theterm is related to and may be analogous to depth buffer, z-buffer andz-depth. The “z” in these latter terms relates to a convention that thecentral axis of view of a camera is in the direction of the camera'sz-axis, and not to the absolute z-axis of a scene. The depth map is apicture where “x” and “y” represent space, and the color of each pixelrepresents its height, “z,” (either from the plane or from a virtualcamera). These images are usually grayscale with white being closest andblack being furthest away. Sometimes the ordering may be reverse, withblack being closest and white being furthest away. The grayscale palettecan be replaced by mapping greyscale information to a modifiablereference gradient, resulting in the wavelength/color spatially encodedimage. Similarly, depth maps produced by image capture devices, e.g.,Kinect, Lytro cameras or a stereo camera in conjunction with conversionsoftware, can be used to shade or colorize the imagery, by mapping thedepth maps to modifiable reference gradients.

As described earlier, the shader tool may be programmed to provide colorbased spatial encoding to an object or scene based on thedistance/depth. For example, shader tool may be programmed to mapvarying color to depth information, by use of linear color gradients orcolor models. In some embodiments, a linear color gradient or a colorsequence is a set of colors arranged in a linear order. Different colorsequences may be created and stored in a gradient library, and a shadertool can be programmed to use any of the color sequences. Examples ofcolor sequences include RGB, RWB (red, white, blue) and non-linear colormodels like HSV (hue, saturation, and value), HSB (hue, saturation, andbrightness), or HSL (hue, saturation, and lightness). Typically, ashader tool is programmed to change the color of a portion of the sourcecontent depending on the depth value associated with the portion of thesource content. The color would change in a manner determined by thecolor sequence used by the shader tool.

In some embodiments, a size change of an image can present a perceptionof z-axis motion of the image towards and away from the viewing window.The content-generation system 1205 can use the below techniques forcausing the 3D spatial image 1225 to appear to move towards and/or awayfrom the viewer 1230.

FIG. 13 is a relationship map 1300 that depicts relationships between azoom parameter and other parameters of an image, consistent with variousembodiments. As depicted in block 1305, in some embodiments, when theimage in the 2D content gets smaller, the image in the 3D spatial imageundergoes a linear motion away from the viewer, and when the image inthe 2D content gets bigger, the image in the 3D spatial image undergoesa linear motion towards the viewer. That is, the zoom parameter goesfrom near to far, while changing image size from bigger to smaller.

Block 1310 depicts a relationship between the zoom parameter and thecolor parameter of the image. For example, by changing the color of theimage from a color sequence, a perception of z-axis motion of the imagetowards and away from the viewing window can be provided in the 3Dspatial image.

Block 1315 depicts a relationship between the zoom parameter and theluminance parameter of the image. In some embodiments, by changing theluminance of the image, a perception of z-axis motion of the imagetowards and away from the viewing window can be provided in the 3Dspatial image. For example, by decreasing the luminance of an image(without color/hue shifts) in the 2D content, the image in the 3Dspatial image undergoes a linear motion away from the viewer, and byincreasing the luminance of the image (without color/hue shifts) in the2D content, the image in the 3D spatial image undergoes a linear motiontowards the viewer. In some embodiments, luminance information of the 2Dimage is specified by the reference gradient or color model, in additionto hue and other color information. Decreasing and increasing theluminance of image elements, which is different from hue shift, isuseful for varying an image element's spatial depth, without color/hueshifts.

Block 1320 shows a relationship between the image distance blurparameter and the zoom parameter in a non-linear manner. By varying thedistance blur parameter from no blur to high blur, the image in 3Dspatial image appears to move from closer to the viewer to away from theviewer.

Various other parameters of the image, e.g., 2D depth cues, alpha, etc.can be changed to vary the zoom parameter of the image, that is, causethe image to appear to move towards and away from the viewer.

In addition to image, object, subject or scene capture with deviceswhich capture and provide depth information, such as the Kinect orLytro, traditional green screen techniques may be used to generate the2D content. In some embodiments, a green screen technique is a method ofphotographing or filming an actor or an object against a greenmonochrome backdrop, and replacing the backdrop area (typicallybackground) with a different image using a color filter. In someembodiments, real world scenes, objects and human subjects can also bespatially displayed on either viewing configurations. Traditional greenscreen techniques can be used to capture objects and subjects. Theobjects or subjects can be colorized for proper spatial placement withina 3D scene. The 3D scene can be a mixture of many elements. The capturedarea of the green monochrome backdrop may be replaced by transparencychannel information in a RGBA image. This can allow for alpha compostingas described earlier. 2D images captured via green screen techniques maybe shaded or colorized according to the desired depth position, bysweeping the spectrum of a ‘reference gradient’ or color model, alongwith image scaling and other techniques, e.g., as described with zoomparameter.

FIG. 14 is an example picture 1400 of a human subject captured usingtraditional green screen techniques for generating a 2D color-encodedcontent, consistent with various embodiments. The human subject can becaptured using a video camera. Once captured, the multimedia file havingthe captured video can be accessed and the subject can be isolated fromthe backdrop using the content-generation system 1205 and then colorizedto generate a color-encoded 2D content, which can be placed into aspatial scene using the 3D imaging system.

FIG. 15 is an example picture 1500 of the color-encoded human subject ofFIG. 14 displayed as a 3D spatial image in the infinity viewingconfiguration of the 3D imaging system, consistent with variousembodiments. The human subject is colorized using the content-generationsystem 1205 for spatial placement, e.g., colored with a specified colorto form the human subject closer the viewer in the 3D spatial image.

As described earlier, the 2D content can be (a) images or videos of realworld objects, subject or scenery, (b) CGI, or (c) a combination ofboth. Regardless of the type of the 2D content, the 2D content can becolor encoded with modifiable color sequences or color models.Compatible images and files containing information about an image may beshared among various image processing methods for creating a 3D spatialscene which is to be graphically rendered as a 2D color encoded image.In some embodiments, it is desired to allow the different contentelements move between different video, 3D or imaging environments.

FIG. 16 is a block diagram illustrating an area of attention in whichfront or foreground objects of a 3D spatial image are to be formed,consistent with various embodiments. The area of attention 1605 andcircumferential area 1610, which is area around the area of attention1605 and usually background, relate to the window parallax perceptualenhancement. The area of attention 1605 is an area in the field of view(FOV) of the viewer in which the viewer may see the entirety of thecontent formed in that area. In some embodiments, the area of attention1605 and circumferential area 1610 are areas on the 2D color-encodedcontent 1220 that enable at the content production stage, for defininghow much of the viewable content will be seen by the viewer at thecenter of the viewing window, e.g., viewing window 1035 of FIG. 10B. Ifthe viewer is looking through the center of the viewing window, a FOV ofthe scene in the 3D spatial image 1225 is slightly larger than the areaof attention 1605. Therefore, the viewer may see all the imagerycontained within the area of attention 1605 in addition to a smallamount of the scene in the circumferential area 1610. As the observermoves away from the center of the viewing window, e.g., to his left asillustrated in FIG. 10C, more of the circumferential area 1610, e.g.,background of the scene will come into view and some of the area ofattention 1605 may go out of the view. This is due to the spatialperceptual enhancement of window parallax.

In creation of a scene to be viewed as a 3D spatial image 1225, caremust be taken as to align the imagery, e.g., at least the foregroundobjects that have to formed closest to the viewer, within the area ofattention 1605, so that when the viewer is looking through the center ofthe viewing window all the imagery that the user is supposed to see isvisible. In addition, a small amount of the circumferential peripheralarea may be seen by the viewer when they are looking thought the centerof the viewing window. The content-generation system 1205 can indicateto the user, e.g., the content creator, on the display of thecontent-generation system 1205 what portions of the screen are the areaof attention 1605 and circumferential area 1610, respectively. Forexample, the content-generation system 1205 can generate guidelinesoutlining the area of attention 1605 and the circumferential area 1610.The content creator can align the 2D content within the respective areasaccordingly.

FIG. 17A is an example picture 1700 of a color encoded 2D image withcircumferential peripheral background and scene objects centered aroundarea of attention, consistent with various embodiments. In the examplepicture 1700, a scene object, e.g., a human, that is to be formed as aforeground object in a 3D spatial image is aligned in the area ofattention 1605 and the water in the background is aligned withcircumferential area 1610.

FIG. 17B is an example picture 1705 of a 3D spatial image generated fromthe color encoded 2D image of FIG. 17A in an infinity viewingconfiguration, consistent with various embodiments. In the 3D spatialimage of FIG. 17B, the foreground object, e.g., a human, is formed inthe area of attention 1605 and the water in the background is formed asthe circumferential area 1610.

FIG. 18 is a flow diagram of a process 1800 for generating a 3D spatialimage using the 3D imaging system, consistent with various embodiments.In some embodiments, the process 1800 may be implemented in theenvironment 1200 of FIG. 12. At block 1805, the content-generationsystem 1205 generates 2D color-encoded content, e.g., 2D color-encodedcontent 1220 using at least the techniques described at least withreference to FIGS. 12-15. In the 2D color-encoded content 1220,different portions of the content are encoded with different colorsbased on depth information, which indicates a depth coordinate of thecorresponding portion of the 2D content with respect to other portionsof the 2D content. The 2D color-encoded content is then input to the 3Dimaging system 1210.

At block 1810, the 3D imaging system 1210 displays the 2D color-encodedcontent using an image source, such as an LCD or LED monitor.

At block 1815, the 3D imaging system 1210 generates a 3D spatial image,e.g., 3D spatial image 1225, of the 2D color-encoded content, using anoptical component of the 3D imaging system, e.g., Fresnel lens. Theoptical component generates the 3D spatial image 1225 in a space behindor ahead of the optical component, based on the viewing configuration ofthe 3D imaging system implemented. Regardless of the viewingconfiguration implemented, the optical component forms differentportions of the 3D spatial image 1225 at different depths from theviewer in which a depth of a portion of the generated 3D spatial imageis determined based on a color of that portion.

FIG. 19 is a block diagram of a computer system as may be used toimplement features of the disclosed embodiments. The computing system1900 may be used to implement any of the entities, components, modules,systems, or services depicted in the examples of the foregoing figures(and any other entities described in this specification). The computingsystem 1900 may include one or more central processing units(“processors”) 1905, memory 1910, input/output devices 1925 (e.g.,keyboard and pointing devices, display devices), storage devices 1920(e.g., disk drives), and network adapters 1930 (e.g., networkinterfaces) that are connected to an interconnect 1915. The interconnect1915 is illustrated as an abstraction that represents any one or moreseparate physical buses, point to point connections, or both connectedby appropriate bridges, adapters, or controllers. The interconnect 1915,therefore, may include, for example, a system bus, a PeripheralComponent Interconnect (PCI) bus or PCI-Express bus, a HyperTransport orindustry standard architecture (ISA) bus, a small computer systeminterface (SCSI) bus, a universal serial bus (USB), IIC (I2C) bus, or anInstitute of Electrical and Electronics Engineers (IEEE) standard 1394bus, also called “Firewire”.

The memory 1910 and storage devices 1920 are computer-readable storagemedia that may store instructions that implement at least portions ofthe described embodiments. In addition, the data structures and messagestructures may be stored or transmitted via a data transmission medium,such as a signal on a communications link. Various communications linksmay be used, such as the Internet, a local area network, a wide areanetwork, or a point-to-point dial-up connection. Thus, computer readablemedia can include computer-readable storage media (e.g., “nontransitory” media).

The instructions stored in memory 1910 can be implemented as softwareand/or firmware to program the processor(s) 1905 to carry out actionsdescribed above. In some embodiments, such software or firmware may beinitially provided to the processing system 1900 by downloading it froma remote system through the computing system 1900 (e.g., via networkadapter 1930).

The embodiments introduced herein can be implemented by, for example,programmable circuitry (e.g., one or more microprocessors) programmedwith software and/or firmware, or entirely in special-purpose hardwired(non-programmable) circuitry, or in a combination of such forms.Special-purpose hardwired circuitry may be in the form of, for example,one or more ASICs, PLDs, FPGAs, etc.

Remarks

The above description and drawings are illustrative and are not to beconstrued as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in someinstances, well-known details are not described in order to avoidobscuring the description. Further, various modifications may be madewithout deviating from the scope of the embodiments. Accordingly, theembodiments are not limited except as by the appended claims.

Reference in this specification to “one embodiment” or “an embodiment”means that a specified feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the disclosure. The appearances of the phrase “in one embodiment” invarious places in the specification are not necessarily all referring tothe same embodiment, nor are separate or alternative embodimentsmutually exclusive of other embodiments. Moreover, various features aredescribed which may be exhibited by some embodiments and not by others.Similarly, various requirements are described which may be requirementsfor some embodiments but not for other embodiments.

The terms used in this specification generally have their ordinarymeanings in the art, within the context of the disclosure, and in thespecific context where each term is used. Terms that are used todescribe the disclosure are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the disclosure. For convenience, some termsmay be highlighted, for example using italics and/or quotation marks.The use of highlighting has no influence on the scope and meaning of aterm; the scope and meaning of a term is the same, in the same context,whether or not it is highlighted. It will be appreciated that the samething can be said in more than one way. One will recognize that “memory”is one form of a “storage” and that the terms may on occasion be usedinterchangeably.

Consequently, alternative language and synonyms may be used for any oneor more of the terms discussed herein, nor is any special significanceto be placed upon whether or not a term is elaborated or discussedherein. Synonyms for some terms are provided. A recital of one or moresynonyms does not exclude the use of other synonyms. The use of examplesanywhere in this specification including examples of any term discussedherein is illustrative only, and is not intended to further limit thescope and meaning of the disclosure or of any exemplified term.Likewise, the disclosure is not limited to various embodiments given inthis specification.

Those skilled in the art will appreciate that the logic illustrated ineach of the flow diagrams discussed above, may be altered in variousways. For example, the order of the logic may be rearranged, substepsmay be performed in parallel, illustrated logic may be omitted; otherlogic may be included, etc. Without intent to further limit the scope ofthe disclosure, examples of instruments, apparatus, methods and theirrelated results according to the embodiments of the present disclosureare given below. Note that titles or subtitles may be used in theexamples for convenience of a reader, which in no way should limit thescope of the disclosure. Unless otherwise defined, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this disclosurepertains. In the case of conflict, the present document, includingdefinitions will control.

I/We claim:
 1. An apparatus, comprising: an image source that isconfigured to display a color-encoded two dimensional (2D) content,wherein different portions of the 2D content are encoded with differentcolors based on a depth at which the different portions are to be formedfrom a user; and an optical component that includes a pair of lensesconfigured to generate a three dimensional (3D) spatial image of the 2Dcontent, wherein the 3D spatial image is viewable as 3D content by theuser without the use of 3D eyewear, wherein the optical component isconfigured to form different portions of the 2D content at differentdistances from the optical component to generate the 3D spatial image,wherein the different portions are formed at the different distancesbased on the color of the different portions of the 2D content, whereinthe optical component generates the 3D spatial image in a space betweenthe optical component and the user.
 2. The apparatus of claim 1, whereinthe pair of lenses is a pair of Fresnel lenses.
 3. The apparatus ofclaim 1, wherein the pair of lenses includes a first lens of the pairand a second lens of the pair that are spaced a specified distance apartand with a side of the first lens having multiple grooves facing a sideof the second Lens having the grooves.
 4. The apparatus of claim 3,wherein the specified distance is determined as a function of the focallength of each lens of the pair of lenses.
 5. The apparatus of claim 1,wherein the optical component includes a first side and an oppositesecond side, wherein a first lens of the pair of lenses facing the imagesource forms the first side and a second lens of the pair of lensesspaced apart from the first lens forms a second side of the opticalcomponent, wherein the optical component is configured to generate the3D spatial image in a space between the user and the second side whenthe light corresponding to the 2D content from the image source passesfrom the first side to the second side.
 6. The apparatus of claim 5,wherein the optical component is positioned in front of the image sourceat a first specified distance between the image source and the firstlens.
 7. The apparatus of claim 6, wherein the first specified distanceis determined as a function of the focal length of the pair of lenses.8. The apparatus of claim 1 further comprising: a content-generationsystem that is configured to encode the 2D content with a plurality ofcolors from a color sequence, wherein the content-generation system isconfigured to encode a specified portion of the 2D content with aspecified color from the colors based on a position at which thespecified portion is to be generated in the 3D spatial image withrespect to other portions of the 2D content.
 9. The apparatus of claim8, wherein the content-generation system is configured to encode the 2Dcontent by: analyzing a data file having the 2D content to identifydifferent portions of the 2D content, obtaining relative positioninformation of the different portions of the 2D content, wherein therelative position information includes depth information between thedifferent portions, and encoding the different portions of the 2Dcontent based on the depth information.
 10. The apparatus of claim 8,wherein the content-generation system is configured to encode thedifferent portions by: encoding a first portion of the portions that isto be displayed farthest from the optical component with a first color,encoding a second portion of the portions that is to be displayednearest to the optical component with a second color, and encoding athird portion of the portions that is to be displayed between the firstportion and the second portion with a third color, wherein displayingdifferent portions of the 2D content at different distances from theoptical component makes the 2D content appear as 3D content.
 11. Theapparatus of claim 10, wherein the second portion acts as a backgroundof the 3D spatial image and the first portion acts as a foreground ofthe 3D spatial image.
 12. The apparatus of claim 10, wherein thecontent-generation system is configured to control a size of the firstportion by adjusting a zoom parameter for the first portion.
 13. Theapparatus of claim 10, wherein the content-generation system isconfigured to control a distance at which the first portion is generatedby adjusting a gradient of the first color.
 14. The apparatus of claim 1further comprising: a mask system that is positioned between the opticalcomponent and the user and configured to cover edges of the pair oflenses, wherein the mask system is configured to enhance a spatialperception of the 3D spatial image.
 15. The apparatus of claim 14,wherein the mask system includes a first mask that is positioned infront of the optical component and a second mask that is positioned infront of the first mask, wherein the first mask has a first opening andthe second mask has a second opening that overlaps with a portion of thefirst opening, the second opening being smaller than the first opening,and wherein the 3D spatial image is projected into the space between theuser and the optical component through the first opening and the secondopening.
 16. The apparatus of claim 15, wherein the 2D content isgenerated to project a specified portion of the 2D content in the spacebetween the user and the optical component centered in areacorresponding to the second opening.
 17. An apparatus, comprising: animage source that is configured to display a color-encoded twodimensional (2D) content; and an optical component that includes a lensconfigured to generate a three dimensional (3D) spatial image of the 2Dcontent, wherein the optical component generates the 3D spatial image ina space behind the optical component and on a side of the opticalcomponent facing the image source, wherein the optical component isconfigured to form different portions of the 2D content at differentdistances from the optical component based on the color of the differentportions of the 2D content, wherein the 3D spatial image is viewable as3D content by a user without the use of 3D eyewear.
 18. The apparatus ofclaim 17, wherein the lens is a Fresnel lens.
 19. The apparatus of claim17, wherein the lens is positioned in front of the image source with aside of the lens having multiple grooves facing the user and anotherside of the lens facing the image source.
 20. The apparatus of claim 17,wherein the optical component is further configured to generate anapparent image source when the image source is viewed through the lens,the apparent image source being a magnified view of the image source.21. The apparatus of claim 20, wherein the optical component is furtherconfigured to generate the apparent image source at optical infinity.22. The apparatus of claim 17 further comprising: a content-generationsystem that is configured to encode the 2D content with a plurality ofcolors from a color sequence, wherein the content-generation system isconfigured to encode different portions of the 2D content with differentcolors from the color sequence based on a position at which thecorresponding portion is to be generated in the 3D spatial image withrespect to other portions of the 2D content.
 23. A method comprising:generating, using a computer system, a color-encoded two-dimensional(2D) content, wherein different portions of the 2D content is encodedwith different colors based on depth information, the depth informationindicating a depth coordinate of the corresponding portion of the 2Dcontent in a three-dimensional (3D) space; displaying, using a 2D imagesource, the color-encoded 2D content; and generating, using an opticalcomponent, a 3D spatial image of the color-encoded 2D content, whereinthe optical component generates the 3D spatial image in a space behindor ahead of the optical component, wherein a depth of a portion of thedifferent portions in the generated 3D spatial image is determined basedon a color of the portion.
 24. The method of claim 23, whereingenerating the 3D spatial image includes generating the 3D spatial imageusing a pair of lenses and forming the 3D spatial image in a spacebetween a user and the pair of lenses.
 25. The method of claim 23,wherein generating the 3D spatial image includes generating the 3Dspatial image using a single lens, and forming the 3D spatial image in aspace behind the single lens.